FM Power Base

The FM Power Base, similar to Sega’s original Power Base Converter, allows you to play Sega Master System games on the Sega Genesis / Megadrive. In addition to this, the FM Power Base includes a YM2413 FM Synthesizer, present only in Japanese Master System consoles, which enables an FM soundtrack for most games that support one (some exceptions apply, read further).

Specifications

FM Synthesizer

The FM Synthesizer used in the Japanese Master System is the Yamaha YM2413. It is a synthesizer composed of 15 hard-coded instruments settings and 1 user-defined instrument. The YM2413 outputs two waveforms, RO (Rhythm) and MO (Melody) but this is not stereo. RO contains the percussive sounds and MO contains the melodic sounds; the two outputs are mixed together into both left and right channels.

Replaceability

The YM2413 synthesizer in the FM Power Base is installed in a socket and can easily be replaced without any soldering. While every YM2413 is pre-screened in my ship prior to being installed in an FM Power Base, some will fail. Simply use a flat object, such as a flat screwdriver to carefully remove the existing chip and replace it with a new one which can easily be found on eBay for cheap.

Failure Rate

YM2413 chips purchased from China and tested in my shop have approximately a 15% failure rate. These range from no sound to garbled sound to extreme short circuits. I discard all of the bad chips – rest assured that no bad chips are installed in any FM Power Base that is sold.

Here is a quick video of what those bad chips sound like!

Audio Output Impedance

The audio output impedance of the FM Power Base is 75 ohms, to match the input impedance of the Model 1 Sega Genesis cartridge port audio inputs. The input impedance of the Sega Genesis model 2 is significantly higher.

Compatibility

Consoles

The Power Base Mini is compatible with all regional variants of the Sega Genesis / Megadrive Model 1 and 2.

Region

The Power Base Mini has the same region as the Genesis / Megadrive it is being used on. While the Sega Master System is generally region-free, there are several games such as Wonder Boy III which check the console’s region before deciding to use the FM chip. In Wonder Boy’s case, the FM audio will only run on a Japanese Master System. A region switch modded Genesis / Megadrive can be used with this games to change the region of the FM Power Base to allow the FM audio soundtrack to be played.